It has been recognized for sometime that persons, such as law enforcement officers and members of the armed forces and others whose work requires them at times to wear heavy protective clothing, e.g., bulletproof (“ballistic”) vests, are prone to becoming seriously overheated and very uncomfortable, especially in those body areas covered by such clothing. This overheating results from the fact that the natural heat of the body is trapped inside heavy protective clothing and tends to accumulate, causing body temperature to rise and thereby triggering the body's own natural perspiration defense to such a condition. Unfortunately, with the protective clothing still in place, perspiration is unable to evaporate and thereby counter the overheating effect of the clothing. Because the ultimate effect of wearing heavy protective clothing over a period of many hours can lead to skin rashes and other skin eruptions or may even so affect the wearer overall as to cause other abnormal physical reactions such as temporary collapse, cardiac or pulmonary reactions, etc., a number of approaches have been developed to alleviating the severe overheating and discomfort that habitual wearers of heavy protective clothing normally experience.
Many of these approaches involve the creation of pockets or channels in the protective clothing for circulating coolants of some nature. Some examples may be found in: (1) U.S. Pat. No. 3,610,323 to Troyer wherein tubular networks in the garment carry cool water containing a refrigerant which is gradually heated by the wearer's body heat, and is then pumped out by a hand operated pump that the wearer controls, through capillary openings in the tubes and is replaced by fresh coolant liquid from an auxiliary source; and (2) U.S. Pat. No. 4,998,415 describes “body cooling” approaches comprising a vest and a headband each equipped with flexible tubes through which a liquid coolant is fed from an auxiliary pressurized container. As the wearer's body heat increases, the coolant vaporizes and is passed to an auxiliary compressor, followed by a condenser which reliquefies it and returns it to the auxiliary pressurized container. Meanwhile additional coolant from the container is pumped into the flexible tube system of the wearer's vest and head band, and the entire cycle is repeated over and over. This patent refers to a number of prior devices, including the Troyer U.S. Pat. No. 3,610,323 which operate generally on a principle of cycling liquid coolant through flexible tubing of a protective garment and discarding or recycling the coolant material when body heat has vaporized it, followed by circulating a fresh increment of coolant into the garment.
Other types of garments operating on similar principles, all requiring liquid or gas for replenishing are described in, e.g. U.S. Pat. No. 6,349,412 to Dean; U.S. Pat. No. 5,255,390 to Gross et al: U.S. Pat. No. 3,348,236 to Copeland, U.S. Pat. No. 5,201,365 to Siegel and U.S. Pat. No. 5,005,216 to Blackburn et al.
Still other known approaches involve garments that can be fitted with replaceable gel packs of coolants such as disclosed by Steele et al in U.S. Pat. Nos. 5,146,625 and 5,305,471 and by Colvin et al in U.S. Pat. No. 5,415,222. The latter discloses a garment which contains pouches containing encapsulated fluid comprising low melting paraffinic materials that are caused to liquefy by the wearer's body heat and are then replaced. The liquefied contents of the pouches may be allowed to resolidify and may be reused or discarded and, in either event, are replaced by fresh pouches of the same type. U.S. Pat. No. 5,524,293 to Kung shows a vest arranged to receive flexible cooled water or ice containing vessels, wherein the vessels must be replaced as the ice melts and warms or as the water warms.
U.S. Pat. No. 3,429,138 to Goldmerstein involves a separate interior vest equipped with, e.g., a sponge soaked with water or coolant. In this case, the vest itself is also soaked in water. Stuebner et al U.S. Pat. No. 4,580,408 shows a multilayer water saturated vest for motocross riders which cools the wearer at the water in each layer evaporates in successive stages. U.S. Pat. No. 5,755,110 discloses a vest with seamed partitions which contain beads of polyacrylamide or another absorbent for water or other coolant liquid. This vest has air intake openings in each seamed conduit and is equipped with one-way intake valves and one-way exhaust valves operable by the wearer's respiration which act alternately to draw more air in and exhaust warmed air. The beads may be re-wetted by soaking the garment in the coolant medium. Frank et al U.S. Pat. No. 6,128,784 also discloses a self-ventilating vest operated by the wearer's respiration which allows both intake of air and exhaustion of air.
While the foregoing are only a sampling of prior art garments which might substitute for or add to heavy protective garments and enable some cooling of the body of a person whose occupation requires the wearing of heavy protective clothing, it is clear that all have some disadvantages, even while providing some cooling effects.
Protective clothing is in itself extremely cumbersome and heavy. Modifications that require the wearer to be burdened with an auxiliary container that is a source of coolant medium are often totally impractical. If essentially stationary, they restrict the protective clothing wearer's freedom of movement. If portable, they represent an added burden upon a person who may also be laden with other heavy gear, such as firearms, ammunition, flashlights, handcuffs, radio equipment, etc.
Garments equipped with replaceable gel packs, coolant cartridges, etc., represent an additional inconvenience to the wearer in that he or she must ensure that replacements are readily available when needed. In addition, these accoutrements add to the weight of the garment and may increase wearer discomfort in the same way that the need to carry a pressurized tank of coolant material does.
To the extent some of the cited prior art requires an extra internal garment for cooling that must be re-wetted from time to time or a self-ventilating garment is burdened with extra weight by reason of including flexible tubes, intake and exhaust valves, etc. problems may constantly arise due to inadvertent punctures, jamming of valves and other mishaps. All of these added concerns to which the wearer must be alert are an added burden upon the minds of personnel whose jobs are often fraught with external danger of a serious nature requiring them to exercise intense alertness and to have minimal mental distraction.
It is an object of this invention to provide a lightweight self-operable apparatus that can easily be worn in addition to a protective vest or other heavy and often cumbersome clothing.
Another object is to provide air cooling of the body which the wearer can be easily direct to spots at which it is most needed.
Still another object is to provide a simple and easily operatable cooling method requiring no extraneous pressuring tanks, coolant packs or other paraphernalia, which cooling method is operatable in any environment and virtually at any time, at the option of the wearer.